We have also located several other surveys from the mid-1960s through the 1970s that show a similar pattern. In
particular, the ten-nation “Images of the World in the Year 2000” study, conducted in 1967, and the twelve-nation Gallup-
Kettering Survey, from 1975, both yield further evidence consistent with an important and positive well-being-GDP
gradient. Subsequent cross-country data collections have become increasingly ambitious, and analysis of these data has
made the case for a linear-log relationship between subjective well-being and GDP per capita even stronger, while also
largely confirming that the magnitudes suggested by these early studies were quite accurate.
Figure 2 presents data on life satisfaction from each wave of the World Values Survey separately; illustrating the
accumulation of new data through time (We turn to the data on happiness from this survey below, in Figure 5).12 In the
early waves of the survey the sample consisted mostly of wealthy countries; given the limited variation in income, these
samples yielded suggestive, but not definitive, evidence of a link between GDP and life satisfaction. As the sample
expanded, the relationship became clearer. In each wave the regression line is upward sloping, and the estimated
coefficient is statistically significant and similar across the four waves, with its precision increasing in the later waves. We
also plot estimates from locally weighted (or lowess) regressions, to get a sense of whether there are important deviations
from the linear-log functional form.13 In the earliest waves the small number of countries and limited heterogeneity in
income across countries made it difficult to make robust inferences about the relationship between life satisfaction and
economic development. Nonetheless, pooling data from all four waves and allowing wave fixed effects yields an estimate
of the satisfaction-income gradient of 0.40 (se=0.04, clustering by country), and an F-test reveals that wave-specific
slopes are jointly statistically insignificant relative to a model with a common slope term (F3,78=1.98).
In some cases the expansion of the World Values Survey to include poorer countries resulted in explicitly
unrepresentative samples.14 For example, Argentina was included in the 1981-84 wave, but the sample was limited to
urban areas and was not expanded to become representative of the country overall until the 1999-2004 wave. Chile,
China, India, Mexico, and Nigeria were added in the 1989-93 wave, but their samples largely consisted of the more
educated members of society and those living in urban areas. These limitations are spelled out clearly in the survey
documentation, but have been ignored in most subsequent analyses. The non-representative samples typically came from
poorer countries, and involved sampling richer (and hence likely happier) respondents. As such, inclusion of these
observations imparts a downward bias on estimates of the well-being-income gradient. We therefore exclude from our
analysis countries which the survey documentation suggests are clearly not representative of the entire population.
Observations for these countries are plotted in Figure 2 using hollow squares. As expected, these observations typically sit
above the regression line. Appendix B provides a comparison of our results when these countries are included in the
analysis, along with greater detail regarding sampling in the World Values Survey.
Subsequently, the 2002 Pew Global Attitudes Survey interviewed 38,000 respondents in forty-four countries
across the development spectrum. The subjective well-being question is a form of Cantril’s (1965) “Self-Anchoring
12 In order to make these data collections consistent, we analyze only adult respondents.
13 The lowess estimator is a local regression estimator that plots a flexible curve.
14 We thank Angus Deaton for alerting us to these limitations in the World Values Survey.